1. Field of the Invention
The invention relates to a transmitted sound insulating member, and a transmitted sound insulating structure including the transmitted sound insulating member. More specifically, the invention relates to a transmitted sound insulating member that blocks a sound from outside a vehicle from entering a vehicle cabin through a door of the vehicle, and a transmitted sound insulating structure including the transmitted sound insulating member.
2. Description of Related Art
There has been a need to block an external sound from entering an automobile cabin through the vicinity of a wing mirror mounting portion of a front door of an automobile. FIG. 12 is an exploded view of a front door according to related art. FIG. 13 is an inner side view of the front door. FIG. 14 is a sectional view of the front door taken along the line XIV-XIV in FIG. 13. FIG. 15 is a sectional view of the front door taken along the line XV-XV in FIG. 13.
As illustrated in FIG. 12, a front door 50 of an automobile is formed by assembling a door outer panel 51 and a door inner panel 52, which are made of steel plates subjected to stamping and joined together, and a door trim 53 to be disposed on the automobile cabin side. As illustrated in FIG. 14, a plurality of plate members 55, 56 and the like are disposed between the door outer panel 51 and the inner panel 52. A sound from outside the automobile travels upward through spaces S1 defined by the upper portions of the inner panel 52 and the plate members 55, 56 and then enters the automobile cabin. Further, there is another route of external sound entry. Specifically, a sound from outside the automobile travels upward through a space S2 defined between the inner panel 52 and the door trim 53 and then enters the automobile cabin.
To block a sound from entering the automobile cabin from the upper end side of the plate members 55, 56 and the inner panel 52, a rubber sealing member 60 is provided to close openings, as illustrated in FIG. 12 (refer to Japanese Unexamined Patent Application Publication No. 2013-107607 (JP 2013-107607 A)). To prevent transmission of a sound traveling through the space S2 defined between the inner panel 52 and the door trim 53, a foamed member 61 having elasticity (e.g. sponge) is provided in the space S2, for example, as illustrated in FIG. 14 (refer to Japanese Unexamined Patent Application Publication No. 2013-256176 (JP 2013-256176 A)).
However, providing only the sealing member 60 illustrated in FIG. 12 and FIG. 14 cannot completely block a sound passing through the space S2 defined between the inner panel 52 and the door trim 53. When the foamed member 61 is provided in the space S2, wire harnesses 71, 72 extending in the up-down direction through the space S2 need to be pressed by the side surface of the foamed member 61, as illustrated in FIG. 14. Thus, there are large spaces S3 between the foamed member 61 and the wire harnesses 71, 72 and between the door trim 53 and the foamed member 61, as illustrated in FIG. 15. This significantly reduces the sound insulating effect.